Apparatus for locating body cavities having signaling indicator

ABSTRACT

An apparatus for locating a body cavity having a fluctuating fluid pressure by signaling the fluctuating pressure when the cavity is entered and then transporting fluid either into or out of the cavity.

This is a continuation of co-pending application Ser. No. 058,400 filedon 06/05/87 now abandoned.

BACKGROUND OF THE INVENTION

This invention relates generally to apparatus for draining fluids frombody cavities and for introducing fluids into body cavities. Moreparticularly, this invention relates to an improved apparatus forpositively locating a body cavity having fluctuating fluid pressure andthen either draining fluids from the cavity or introducing fluids intoit.

An apparatus for draining fluids from body cavities, includingparticularly the pleural cavity, is described in U.S. Pat. No.4,664,660. The apparatus described in that patent includes a ventedhousing having a fluid-receiving chamber, an anti-reflux valve mountedwithin the housing and a catheter, extending from the housing, incommunication with the chamber through the anti-reflux valve.

The apparatus of U.S. Pat. No. 4,664,660 is used in the drainage offluids from the pleural cavity by inserting a solid trocar into thecatheter so that the sharp tip of the trocar extends beyond the distalend of the catheter. A skin incision is then prepared and thetrocar/catheter assembly is introduced into the pleural space throughthe incision. When the trocar is removed from the catheter, fluid drainsfrom the pleural cavity through the catheter and the vented housing.

While the above-described apparatus represents a very importantcontribution to the art, in using it one cannot ascertain whether theopen distal end of the trocar/catheter assembly is properly located inthe pleural cavity until the trocar is removed. Since drainage cannotbegin until the trocar is removed, the proper positioning of thecatheter in the pleural space cannot be determined with the trocar inplace. In addition, damage to the lung, heart and surrounding tissuecould occur if the trocar is not removed as soon as the tip of thetrocar catheter assembly enters the pleural space.

Another apparatus for draining fluids from body cavities, particularlyaspiration of liquids from the pleural cavity, is disclosed in U.S. Pat.No. 4,447,235. The apparatus described in this patent includes acatheter/hollow needle assembly which is inserted into the pleuralcavity. During the insertion procedure, a vacuum is maintained in theneedle with a syringe so that liquid will enter the syringe forobservation by the surgeon when the needle enters the pleural space.This device cannot function unless a vacuum is maintained. Also, itcannot signal subsequent dislocation of the catheter from the pleuralspace or completion of drainage since the syringe is disconnected (andcannot be reintroduced) after the initial insertion of the catheter inthe pleural cavity.

A medical suction device with an indicator flag to signal the pressurebeing developed by the device is described in U.S. Pat. No. 4,404,924.The indicator flag is designed to stand upright when the pressure in thedevice is relatively high and to collapse when suction is developed. Theflag, unfortunately, indicates the state of fill of the suction device,not the satisfactory location of a catheter in the body cavity beingaspirated or the completion of the aspiration procedure. In addition, ithas no application in a procedure conducted without vacuum assistance.

Finally, U.S. Pat. No. 4,164,938 describes a device for diagnosing thepresence of a tension pneumothorax. This device includes a sleeve with aneedle at one end for puncturing the chest wall and extending into thepleural cavity and a diaphragm at the other end which expands when thepressure in the pleural cavity is greater than atmospheric. Since thisdevice does not vent fluid from the pleural cavity, the diaphragm doesnot provide any indication that venting is proceeding or that thepneumothorax has been resolved.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide anapparatus for draining fluids from a body cavity or introducing fluidsinto the cavity which positively locates the body cavity.

It is a further object of the present invention to provide a catheterapparatus in which a trocar is used to facilitate insertion of thecatheter into the cavity, and in which a positive indication that thecavity has been located is provided without removing the trocar.

It is yet another object of the present invention to provide a catheterapparatus for draining fluids from a body cavity which permits thedrainage to commence as soon as the apparatus enters the cavity.

These and other objects of the present invention will be apparent fromthe discussion below.

The present invention is therefore directed to an apparatus fortransporting fluid either into or out of a body cavity having afluctuating fluid pressure. The apparatus includes a conduit forentering the cavity, means for signaling the fluctuation of the fluidpressure in the cavity and means for transporting the fluid either intoor out of the cavity. The signaling means provides a positive indicationthat the cavity has been located.

In one important embodiment, the means for entering the cavity comprisesa catheter and a housing, having an inlet chamber and a dischargechamber, supporting the catheter in sealed fluid communication with theinlet chamber. An inlet port is provided in the housing having a sealfor reversibly receiving a trocar and enabling at least a portion of thetrocar to pass through the inlet chamber and the catheter. The inletport seal is adapted for sealing the chamber both in the absence of thetrocar and upon its insertion and withdrawal. In addition, ananti-reflux valve is mounted in the housing, coupling the inlet chamberto the discharge chamber. The anti-reflux valve permits fluid enteringthe inlet chamber to pass into the discharge chamber, but prevents anyfluid from flowing back into the inlet chamber. Finally, and mostimportantly, this embodiment of the invention also includes means forsignaling the fluctuating fluid pressure in the body cavity, to therebypositively signal that the body cavity has been located.

In another important embodiment of the invention an improvement inapparatus having a conduit with a removable trocar to aid bodypenetration is provided. The improvement comprises a furrow in thetrocar which permits fluid flow through the conduit while the trocar isstill in place in the conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of this invention which are believed to be novel are setforth with particularity in the appended claims. The invention, togetherwith its objects and the advantages thereof, may be best understood byreference to the following description, taken in conjunction with theaccompanying drawings, in which like reference numerals identify likeelements in the several figures and in which:

FIG. 1 is a perspective view of an apparatus in accordance with thepresent invention, showing a trocar inserted into the inlet chamber ofthe apparatus;

FIG. 1A is an elevation view of the rear of the apparatus of FIG. 1;

FIG. 2 is a sectional view of the apparatus of FIG. 1, taken along lines2--2 of FIG. 1A;

FIG. 2A is a partial sectional view of a discharge chamber of analternate embodiment of the apparatus of FIG. 1 in which a dischargeport is provided for removing liquids from the discharge chamber;

FIG. 2B is a partial sectional view of an alternate embodiment of theapparatus of FIG. 1 in which an auditory signal indicative of thefluctuation of fluid pressure is produced;

FIG. 3 is a plan view of the film valve utilized in the apparatus ofFIG. 1;

FIG. 4A is a front elevation view of a furrowed trocar used in thepractice of the present invention;

FIG. 4B is an enlarged sectional view of the trocar of FIG. 4, takenalong lines 4B--4B. of FIG. 4; an

FIGS. 5A and 5B are enlarged sectional views of the domed signalutilized in the apparatus of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The apparatus of the present invention is intended to have applicationin locating and in moving fluids either into or out of body cavitiessuch as the pleural cavity, the spinal epidural space, blood vessels,the gallbladder, the urinary bladder, the kidney pelvis, the brainventricles and the brain subdural and epidural spaces. However, forpurposes of illustration, the discussion below is directed primarily toan embodiment of the invention particularly suited for locating anddraining fluids from the pleural cavity.

An apparatus 10 in accordance with the present invention is illustratedin FIGS. 1, 1A and 2. The apparatus includes a housing 12 having aninlet chamber 14 and a discharge chamber 16. Housing 12 is made of anyrigid, impervious material, such as an acrylic, ABS, polystyrene orpolyvinyl chloride plastic.

Apparatus 10 includes a manifold 17 having a first bore 18 extendingthrough the manifold. Bore 18 is enlarged at its distal end to form arecess 20 to which a cannula 22 is affixed and sealed. A conduit in theform of catheter 24 in turn is affixed and sealed to cannula 22 toprevent the passage of air or other fluids from outside of housing 12into inlet chamber 14.

The proximal end of bore 18 is enlarged to form an inlet port 26,through which trocar 28 can be inserted and withdrawn. A flexiblesealing material 30 is disposed in the inlet port to seal against thetrocar when it is in place and to close off the port when the trocar iswithdrawn.

Sealing material 30 is a highly resilient silicone, although othermaterials exhibiting the desired sealing properties, such as naturallatex, can be used. The sealing material is held in place by a washer 32which is fixed in the end of the inlet port.

A second bore 34 is formed in manifold 17, perpendicular to and in fluidcommunication with bore 18. The second bore extends through the cap fromits top surface 36 down to an annular shoulder 38 formed in the bottomof the manifold.

An anti-reflux valve 40 is secured to shoulder 38. Anti-reflux valve 40is a film valve which is illustrated in FIG. 3. The film valve is veryresponsive to even slight reflux pressures. It is made up of two piecesof virtually any type of plastic film, such as polyethylene, mylar,nylon or PVC, as well as laminates of these materials. The onlyrequirement in choosing the plastic films is that the combination ofplastics do not adhere. Also, it has been found to be preferable in thepresent application to use films with a combined thickness in the rangeof about 3-5 mils. Laminates of nylon and polyethylene are one preferredmaterial. When this laminate is used, the plastic film is used with thepolyethylene sides facing each other.

The edges of the two film members of the valve are heat sealed to eachother with a tortuous profile 42 at the closed edges of the valve inorder to prevent fluid leakage. The cracking resistance or thresholdpressure at which the valve permits fluid to flow through it can beadjusted by varying the thickness of the plastic films and the lengthand width of the valve passage 43.

Other anti-reflux valves which are sufficiently sensitive to refluxpressures to produce a discernible movement in the signaling means(described below) can be used. The "Heimlich valve" utilized in U.S.Pat. No. 4,664,660, described above in the Background of the Invention,for example, can be used in the present application but is lesspreferred than the film valve, because the Heimlich valve is far lesssensitive to reflux pressures. The Heimlich valve is described in U.S.Pat. No. 3,463,159.

The space defined by bore 18 and bore 34 together comprise the inletchamber 14 of the apparatus. The inlet chamber is separated from outletchamber 16 by anti-reflux valve 40.

Catheter 24 is formed of a stainless steel spring core 48 covered withan elastomer 50, which preferably is present in the form of a siliconecoating on the spring. The tip 52 of the catheter is preferably made ofa resilient polymer, such as polyurethane or silicone rubber, and isbonded to the end of the spring core.

The tip of the catheter is open at 54 to permit trocar 28 to passthrough. Elastomer covering 50 of the catheter may have a plurality ofports 56, in addition to the opening at the tip, to facilitate drainingbetween the exposed coils of spring 48, and to insure that drainageproceeds in the event that opening 54 is blocked by expanding lungtissue.

Discharge chamber 16 has a series of elongated vent openings 58 (FIG.1A) located behind a protective cover 59. Cover 59 is affixed to housing12 along its sides and undercut to create a passage 61 at its top andbottom through which gaseous fluids vent to the atmosphere. Ahydrophobic filter 60 is fixed in place behind the vent openings toprevent aqueous liquids from escaping the discharge chamber.

A self-adhesive strip 62 is attached to the exterior of the distal wall64 of housing 12. The adhesive strip is covered by a protective releasesheet 66 which is removed prior to installation of the catheter, so thatthe strip can be applied to the patient's skin upon installation of theapparatus.

In addition, a seal cuff 68 is provided about catheter 24, adjacent wall64 of the apparatus which will abut the patient's body. Cuff 68, whichis preferably a sponge silicone or other resilient material, is intendedto prevent tissue emphysema by sealing the perimeter of the catheter atthe wound site where the catheter enters the body.

An absorbent pad 70 is positioned at the bottom and side of thedischarge chamber to absorb small quantities of blood or other liquidswhich may pass through the apparatus when, as in the present embodiment,the principal fluid being drained is air. In an alternative embodiment,where significant amounts of liquid are to be drained, a collection port72 (FIG. 2A) is provided so that the fluid may be continuously withdrawneither under suction or by gravity.

Trocar 28, which is illustrated in FIGS. 4A and 4B, includes a handle 74molded or bonded to its proximal end. The trocar is sized so that itsdistal, pointed tip 76 protrudes beyond the tip 52 of catheter 24 whenthe trocar is fully inserted in the apparatus. Trocar 28 includes afurrow 78 which extends from trocar tip 76 through a point 79 nearhandle 74. The furrow permits fluid communication between the tip 52 ofthe catheter and inlet chamber 34 while the trocar is inserted in thecatheter. Furrow 78 thus permits fluids to be vented from the pluralcavity immediately upon introduction of the catheter, without removal ofthe trocar. Furrow 78 also permits the signaling means (described below)to begin functioning immediately upon entry of the catheter tip into thepleural cavity.

Means for signaling fluctuation of fluid pressure in the pleural cavityis provided in the form of a resilient signal dome 80 which is in fluidcommunication with inlet chamber 14 by way of bore 82 in manifold 17.Signal dome 80 has an annular lip 84 which is sealingly affixed to thetop 36 of manifold 17 so that the dome caps and closes off bore 82. Aclear cover 86 is affixed to the top 36 of manifold 17, to define asignal chamber 88. A vent hole 90 is formed in the cap to permit thesignal dome to freely expand and contract within it.

Signal dome 80 is made of a resilient material, preferably silicone,with a shape and resilience such that the dome will collapse (FIG. 5B)and return to its normal configuration (FIG. 5A) with the fluctuatingpressures in the pleural cavity, producing a pulsating visual indicationof the pleural cavity pressures. In the embodiment illustrated, thesignal dome is molded of silicone and is wider than it is high. It has awall thickness of about 0.012 to 0.015 inches at its base tapering toabout 0.007 inches at its apex, as illustrated in FIG. 5A-5B. In otherapplications the signal dome sensitivity may be adjusted as necessary byvarying, for example, the material from which the signal dome isfabricated, as well as the size and shape of the dome, and its wallthickness and taper.

The functioning of the signal means depends on: (1) changes in pressure(differential pressures) in the body cavity of interest; (2) crackingresistance of the anti-reflux valve, and (3) sensitivity of the signaldome. Since the differential pressures of the body cavity are notcontrollable, the anti-reflux valve cracking resistance and/or thesignal dome sensitivity must be matched to the differential pressures ofthe particular body cavity in order to produce the desired pulsatingmovement in the signal dome. For example, in an application in theepidural space, where the pressures are generally lower than in thepleural cavity, a more sensitive dome and/or an anti-reflux valve with ahigher cracking resistance will be needed.

Naturally, the signaling means include any resilient structures whichpulsate with fluctuating pressure in the system. For example, a flatresilient membrane which expands with increasing pressure and collapsesback to a generally flat position on decreasing pressure would provide asatisfactory alternative to the signal dome illustrated above.

In an alternate embodiment, an auditory signal is provided, either aloneor in conjunction with the visual signal described above. Thus, there isillustrated in FIG. 2B an embodiment in which a hole 92 is made in cover59, passages 61 are closed off and a low velocity whistle 94 is affixedto the cover so that the opening in the whistle 96 is aligned with thehole in cover 59. Thus, the air passing though the discharge chamberwill exit through the whistle, producing a rhythmic auditory signalindicative of the fluctuating pressure in the pleural cavity before thepneumothorax is resolved and either a continuous signal or silence whenthe pneumothorax is resolved. The loudness and sensitivity of the signalwill be a function of the cracking resistance of the anti-reflux valve40, the resistance to air movement of filter 60, and the sensitivity ofthe whistle.

In yet another alternative embodiment of the present invention, once thecatheter is in place in the pleural cavity, a cannula sized to fitwithin the catheter 24 is passed through seal 30, through bore 18 andinto the catheter. A vacuum is then applied to the cannula to rapidlyremove fluids from the pleural space.

In treating traumatic or idiopathic pneumothorax, or for evacuating airfrom the chest following thoracic surgery or percutaneous lung biopsy,the apparatus 10 may be used as follows:

1. If the apparatus is supplied in sterile kit form, the apparatus isremoved from the kit under sterile conditions and the trocar is insertedthrough inlet port 26 so that its tip protrudes from the tip 52 ofcatheter 24.

2. A site is selected, preferably in the second interspace at themidclavicular line.

3. The site is prepared with an antimicrobial agent and a drape isplaced over the site.

4. Local anesthesia is applied at the site.

5. Using a scalpel, a small skin incision is made at the site.

6. The release sheet is removed from the adhesive strip.

7. With the thumb over the trocar handle, the device is positioned atthe incision and the trocar/catheter assembly is passed into the pleuralspace immediately above the superior border of the rib. Catheter 24 ismaintained in a straight condition by the trocar, so that the catheterwill remain rigid and resist bending upon insertion into the bodycavity. In addition, spring 48 prevents any significant compaction ofthe catheter on the trocar during the insertion process.

8. When the catheter tip enters the pleural space, signal dome 80 willbegin to pulsate. When this occurs, the trocar is removed to increasethe rate of fluid flow and prevent damage to the lung. The continuingpulsating movement of the signal dome is observed as the air isevacuated from the pleural cavity and the lung begins to reinflate.

9. When the pneumothorax is resolved and the lung is reinflated thesignal dome stops pulsating and the apparatus can be removed.

While the present apparatus has been described in connection with theremoval of fluids from the pleural cavity, the device may be used in amultitude of other applications, both for removing fluids and forintroducing fluids. For example, it may be used in locating and inmoving fluids either into or out of body cavities such as the pleuralcavity, the spinal epidural space, blood vessels, the gall bladder, theurinary bladder, the kidney pelvis, the brain ventricles, and the brainsubdural and epidural spaces. In introducing fluids, the catheter isinserted in the cavity and then a cannula is introduced through seal 30and into the catheter, whereby the fluids to be introduced are passedthrough the cannula by way of a syringe or other conventional injectiondevice.

For example, in administering an epidural block, the anesthesiologistwould position the trocar/catheter tip in the epidural space relyingupon the pulsating signal dome to positively indicate that the epiduralspace has been located. He or she would then remove the trocar andinsert a syringe containing an appropriate anesthetic and inject theanesthetic into the epidural space.

While particular embodiments of the invention have been shown anddescribed, it will be obvious to those skilled in the art that variouschanges and modifications may be made therein without departing from thespirit and scope of the invention and, therefore, it is intended in theappended claims to cover all such changes and modifications which fallwithin the true spirit and scope of the invention.

What we claim is:
 1. An apparatus for locating a body cavity having afluctuating fluid pressure and transporting fluid either into or out ofthe cavity, comprising:a conduit for entering the cavity; means, incommunication with said conduit, for signaling the fluctuation of thefluid pressure in the cavity when said conduit enters the body cavity,said signalling means comprising a dome-shaped elastomeric elementhaving a wall thickness gradually tapering from its base to its apexwhich pulsates in response to the fluctuating fluid pressure in the bodycavity; and means, in communication with said conduit, for transportingfluid either into or out of the cavity.
 2. An apparatus for locating abody cavity having a fluctuating fluid pressure and transporting fluideither into or out of the cavity, comprising:a conduit, a housing havingan inlet chamber and a discharge chamber, said housing supporting saidconduit in sealed fluid communication with said inlet chamber; an inletport in said housing having inlet port sealing means for reversiblyreceiving a trocar and enabling at least a portion of a trocar to passthrough said inlet chamber and said conduit, said inlet port sealingmeans being adapted for sealing said chamber both in the absence of atrocar and upon insertion and withdrawal of a trocar. anti-reflux valvemeans mounted in said housing, coupling said inlet chamber with saiddischarge chamber, for permitting fluid entering said inlet chamber topass into said discharge chamber while preventing fluid from flowingfrom said discharge chamber into said inlet chamber, and means forsignaling the fluctuating fluid pressure in the body cavity upon entryof the conduit into the body cavity comprising an elastomeric elementwhich pulsates in response to the fluctuating fluid pressure in the bodycavity, wherein said elastomeric element is dome-shaped and thethickness of the wall of said dome-shaped elastomeric element graduallytapers to its apex.
 3. An apparatus for locating a body cavity having afluctuating fluid pressure and transporting fluid either into or out ofthe cavity comprising:a conduit, a resilient cuff provided at the baseof said conduit to seal against the body, a housing having an inletchamber and a discharge chamber, said housing supporting said conduit insealed fluid communication with said inlet chamber; an inlet port insaid housing having inlet port sealing means for reversibly receiving atrocar and enabling at least a portion of a trocar to pass through saidinlet chamber and said conduit, said inlet port sealing means beingadapted for sealing said chamber both in the absence of a trocar andupon insertion and withdrawal of a trocar, anti-reflux valve meansmounted in said housing, coupling said inlet chamber with said dischargechamber, for permitting fluid entering said inlet chamber to pass intosaid discharge chamber while preventing fluid from flowing from saiddischarge chamber into said inlet chamber, and means for signaling thefluctuating fluid pressure in the body cavity upon entry of the conduitinto the body cavity.
 4. An apparatus for locating a body cavity havinga fluctuating fluid pressure and transporting fluid either into or outof the cavity comprising:a conduit, a housing having an inlet chamberand a discharge chamber, said housing supporting said conduit in sealedfluid communication with said inlet chamber, an inlet port in saidhousing having inlet port sealing means for reversibly receiving atrocar and enabling at least a portion of a trocar to pass through saidinlet chamber and said conduit, said inlet port sealing means beingadapted for sealing said chamber both in the absence of a trocar andupon insertion and withdrawal of a trocar, anti-reflux valve meansmounted in said housing, coupling said inlet chamber with said dischargechamber, for permitting fluid entering said inlet chamber to pass intosaid discharge chamber while preventing fluid from flowing from saiddischarge chamber into said inlet chamber, said anti-reflux valve meanscomprising a film valve comprising two pieces of plastic film withclosed edges having a tortuous profile; and means for signaling thefluctuating fluid pressure in the body cavity upon entry of the conduitinto a body cavity.
 5. The apparatus of claim 4, wherein said plasticfilm pieces comprise a nylon/polyethylene laminate.
 6. The apparatus ofclaim 4 wherein said conduit is a flexible catheter.
 7. The apparatus ofclaim 6 wherein said catheter comprises a spring covered by anelastomeric coating.
 8. The apparatus of claim 4 wherein said signalingmeans comprises an elastomeric element which pulsates in response to thefluctuating fluid pressure in the body cavity.
 9. The apparatus of claim4 wherein said signaling means comprises a whistle.
 10. The apparatus ofclaim 9 including a cannula passing through said inlet port sealingmeans and said inlet chamber and into said conduit for transportingfluid either into or out of the cavity.
 11. The apparatus of claim 4wherein a collection port is provided in said discharge chamber forwithdrawing liquids therefrom.